Auto-fit mask

Abstract

Devices and systems with methods for detecting a sealing condition between a patient interface and a patient, and adjusting the patient interface to maintain the patient interface in sealing contact with the patient. The patient interface may include a sealing structure to form a seal on the patient, and a positioning structure to secure the sealing structure to the patient. The patient interface may include a sensor coupled to the sealing structure. A processor determines the sealing condition between the sealing structure and the patient based on a signal from the sensor, and adjusts at least one of the sealing structure and the positioning structure to maintain the sealing structure in sealing contact with the patient. A prediction system predicts a leak between the sealing structure and the patient based on the sensor signal. A learning system learns how to fit the sealing structure to the patient to form a seal.

1 . A patient interface for sealed delivery of a flow of breathable gas to a patient's airway, the patient interface comprising:
 a sealing structure having a seal surface to contact skin on the patient's face;   a positioning structure to secure the sealing structure to the patient's face;   a sensor at the seal surface to directly sense skin touch of the patient's face to the sensor of the seal surface and configured to generate a sensor signal; and   a processor connected with the sensor, the processor configured to determine a sealing condition between the sealing structure and the patient based on the sensor signal, the processor further configured to adjust at least one of the sealing structure and the positioning structure to maintain the sealing structure in sealing contact with the patient.   
     
     
         2 . The patient interface of  claim 1 , wherein the processor is configured to adjust at least one of the sealing structure and the positioning structure based on the determined sealing condition. 
     
     
         3 . The patient interface of any one of  claims 1 - 2 , wherein the patient interface is one of a nasal mask, nasal pillows, a nasal puff, and an oro-nasal mask. 
     
     
         4 . The patient interface of any one of  claims 1 - 3 , wherein the sensor generates a fluctuating sensor signal indicative of an unstable contact between the sealing structure and the patient's face. 
     
     
         5 . The patient interface of any one of  claims 1 - 4 , wherein the processor is configured to generate a warning signal indicating the determined sealing condition. 
     
     
         6 . The patient interface of any one of  claims 1 - 5 , further comprising a power source to power at least one of the sealing structure, the positioning structure, the sensor, and the processor. 
     
     
         7 . The patient interface of  claim 6 , wherein the power is in one of the following forms: a solid state battery, energy harvesting, microturbine, RF, induction coupling, wireless power, and wired power. 
     
     
         8 . The patient interface of  claim 6 , wherein the power source is one of a 5V DC battery, a Lithium cell, a button cell, and a power supply of at least 3.0V. 
     
     
         9 . The patient interface of any one of  claims 1 - 8 , further comprising a display. 
     
     
         10 . The patient interface of  claim 9 , wherein the display is any one of a voltmeter, a computer interface, and a serial monitor. 
     
     
         11 . The patient interface of any one of  claims 1 - 10 , wherein the processor is configured to control adjustment of the sealing structure or the positioning structure to to obtain a direct touch signal from the sensor. 
     
     
         12 . The patient interface of any one of  claims 1 - 11 , wherein the processor is configured to control a flow generator to supply the flow of breathable gas to the patient based on the determined sealing condition. 
     
     
         13 . The patient interface of  claim 12 , wherein the processor instructs the flow generator to start supplying the flow of breathable gas to the patient when the sealing structure is in sealing contact with the patient. 
     
     
         14 . The patient interface of any one of  claims 12 - 13 , wherein the processor instructs the flow generator to stop supplying the flow of breathable gas to the patient when the sealing structure is not in sealing contact with the patient. 
     
     
         15 . The patient interface of any one of  claims 1 - 14 , further comprising a high pass filter to filter a frequency oscillation in the sensor signal. 
     
     
         16 . The patient interface of any one of  claims 1 - 15 , wherein the sealing structure includes a conductive path transmitting the sensor signal to the processor. 
     
     
         17 . The patient interface of any one of  claims 1 - 16 , wherein the sensor of the patient interface is one of a capacitive sensor and a resistive sensor. 
     
     
         18 . The patient interface of any one of  claims 1 - 17 , wherein the processor is configured to determine a distance between the sealing structure and the patient's face based on a sensor signal. 
     
     
         19 . The patient interface of any one of  claims 1 - 18 , further comprising a plurality of sensors arranged at different locations on the sealing structure to determine proximity between different locations on the sealing structure and the patient's face. 
     
     
         20 . The patient interface of any one of  claims 1 - 19 , wherein the determined sealing condition includes any one of (1) an unintentional leak, (2) an adequate contact, and (3) an inadequate contact between the sealing structure and the patient's face. 
     
     
         21 . The patient interface of any one of  claims 1 - 16 , wherein an additional sensor of the patient interface is one of a capacitive sensor, a resistive sensor, a resistive ink bend sensor, a shear sensor, and a piezoelectric film sensor. 
     
     
         22 . A system for predicting an unintentional leak between a patient interface and a patient's face, the system comprising:
 a sealing structure of a patient interface, the sealing structure including a seal surface to contact skin on the patient's face, the seal surface including a sensor to directly sense skin touch of the patient's face, a processor configured to receive a sensor signal from the sensor, the processor configured to predict a likelihood of an unintentional leak between the patient interface and the patient's face based on the sensor signal.   
     
     
         23 . The system of  claim 22 , wherein the likelihood of a seal leak includes one of an imminent leak and a leak during the same therapy session. 
     
     
         24 . The system of any one of  claims 22 - 23 , wherein a sensor signal from a further sensor of the patient interface indicates at least one of force, pressure, seal contact pressure, shear, friction, orientation, position, transcutaneous oximetry, and tissue hypoperfusivity. 
     
     
         25 . The system of any one of  claims 22 - 24 , wherein the processor predicts the likelihood of an unintentional leak based on the sensor signal and a time element associated with the sensor signal. 
     
     
         26 . The system of any one of  claims 22 - 25 , wherein the processor is configured to detect an onset of at least one of a pressure sore and patient discomfort. 
     
     
         27 . The system of any one of  claims 22 - 26 , wherein the processor is configured to adjust the patient interface to prevent the unintentional leak from occurring. 
     
     
         28 . The system of  claim 27 , wherein the processor is configured to issue an instruction to tighten a headgear strap of the patient interface. 
     
     
         29 . The system of any one of  claims 22 - 28 , wherein the processor predicts the unintentional leak:
 determining a rate of change of a sensor reading, and   comparing the rate of change to a predetermined threshold.   
     
     
         30 . The system of  claim 29 , wherein the processor determines that an unintentional leak is likely to occur when the rate of change exceeds the predetermined threshold. 
     
     
         31 . The system of any one of  claims 22 - 30 , wherein the processor is configured to determine whether a patient is shifting based on an orientation signal obtained from an orientation sensor. 
     
     
         32 . The system of  claim 31 , wherein the processor initiates a preventive action to compensate for orientations known to increase the likelihood of a unintentional leak. 
     
     
         33 . The system of any one of  claims 22 - 32 , wherein the processor is configured to determine hypoperfusion. 
     
     
         34 . A system for learning how to fit a patient interface to a patient's face to form a seal:
 a memory storing at least one historical setting of a patient interface for fitting the patient interface to the patient's face; and   a processor configured to analyze the at least one historical setting, and determine a setting to be applied to the patient interface to form a seal with the patient's face.   
     
     
         35 . The system of  claim 34 , wherein the historical setting is a user preferred setting. 
     
     
         36 . The system of any one of  claims 36 - 35 , wherein the memory is a solid state memory. 
     
     
         37 . The system of any one of  claims 34 - 36 , wherein the historical setting includes a patient interface parameter associated with at least one of a strap length, strap elasticity modulus, force, pressure, position, tilt angle and shape. 
     
     
         38 . The system of any one of  claims 34 - 37 , wherein the processor is configured to analyze a plurality of historical settings, determine a trend of the historical settings, and develop an optimal setting for fitting the patient interface to the patient. 
     
     
         39 . The system of any one of  claims 34 - 38 , wherein the setting to be applied to the patient interface is an average of the at least one historical setting. 
     
     
         40 . A patient interface for sealed delivery of a flow of breathable gas to a patient's airway, the patient interface comprising:
 a sealing structure to form a seal on the patient's face;   a plurality of capacitive sensors coupled to the sealing structure, each sensor disposed at a different location on the sealing structure, each sensor configured to detect proximity between the sealing structure and the patient's face, each sensor adapted to couple with a processor to determine a sealing condition between the sealing structure and the patient's face based on a signal strength detected by each sensor.   
     
     
         41 . The patient interface of  claim 40 , wherein the processor is configure to identify a sealing condition at each sensor location on the sealing structure 
     
     
         42 . The patient interface of any one of  claims 40 - 41 , wherein the processor determines the sealing condition by comparing the signal strength to a predetermined threshold. 
     
     
         43 . The patient interface of  claim 42 , wherein the processor determines that a touch has occurred or an excessive force has been applied against the patient's face, when the signal strength exceeds the predetermined threshold. 
     
     
         44 . The patient interface of any one of  claims 42 - 43 , wherein the processor determines no touch or an inferior touch has occurred, when the signal strength does not exceed the predetermined threshold. 
     
     
         45 . The patient interface of any one of  claims 40 - 44 , wherein at least one of the capacitive sensors includes a plurality of resistors in series. 
     
     
         46 . The patient interface of any one of  claims 40 - 45 , wherein at least one of the capacitive sensors includes an exposed metal contact area allowing direct contact with the patient's face. 
     
     
         47 . The patient interface of any one of  claims 40 - 46 , wherein at least one of the capacitive sensors is covered by a layer of insulation. 
     
     
         48 . The patient interface of any one of  claims 40 - 47 , wherein at least one of the capacitive sensors includes a copper tape. 
     
     
         49 . The patient interface of any one of  claims 40 - 48 , wherein at least one of the capacitive sensors has an oblong configuration. 
     
     
         50 . The patient interface of any one of  claims 40 - 49 , wherein at least one of the capacitive sensors is weaved into the sealing structure by at least one conductive thread. 
     
     
         51 . A patient interface for sealed delivery of a flow of breathable gas to a patient's airway, the patient interface comprising:
 a sealing structure to form a seal on the patient's face; and   a capacitive sensor including a copper tape coupled to the sealing structure, the sensor adapted to couple with a processor to determine proximity between the sealing structure and the patient's face.   
     
     
         52 . The patient interface of  claim 51 , wherein the copper tape has an oblong shape. 
     
     
         53 . The patient interface of any one of  claims 51 - 52 , wherein the copper tape has dimensions of approximately 15 mm by 10 mm by 0.06 mm. 
     
     
         54 . The patient interface of any one of  claims 51 - 53 , wherein the copper tape is attached to an inner membrane of the sealing structure. 
     
     
         55 . The patient interface of any one of  claims 51 - 54 , wherein the copper tape is attached to an outer membrane of the sealing structure. 
     
     
         56 . A patient interface for sealed delivery of a flow of breathable gas to a patient's airway, the patient interface comprising:
 a sealing structure to form a seal on the patient's face; and   a capacitive sensor including textile coupled to the sealing structure, the sensor adapted to couple with a processor to determine proximity between the sealing structure and the patient's face.   
     
     
         57 . The patient interface of  claim 56 , wherein the capacitive sensor is weaved into the sealing structure by a conductive thread. 
     
     
         58 . The patient interface of any one of  claim 56 - 57 , wherein capacitive sensor includes a conductive path to transmit information to the processor. 
     
     
         59 . A patient interface for sealed delivery of a flow of breathable gas to a patient's airway, the patient interface comprising:
 a sealing structure to form a seal on the patient's face; and   a resistive sensor coupled to the sealing structure, the resistor sensor including a pair of parallel conductive elements placed on the sealing structure, the sensor adapted to couple with a processor to determine proximity between the sealing structure and the patient's face.   
     
     
         60 . The patient interface of  claim 59 , wherein the resistive sensor is exposed on an outer membrane of the sealing structure. 
     
     
         61 . The patient interface of any one of  claims 59 - 60 , wherein the resistive sensor includes material coated in conductive paint. 
     
     
         62 . The patient interface of any one of  claims 59 - 61 , wherein the resistive sensor includes a pair of parallel touch pads. 
     
     
         63 . The patient interface of  claim 62 , wherein each touch pad includes a conductive path. 
     
     
         64 . The patient interface of  claim 62 , wherein the pair of parallel touch pads is arranged in an interlaced or cross-linked fashion. 
     
     
         65 . The patient interface of any one of  claims 59 - 64 , wherein resistive sensor has a tin-coated copper wire arranged in an interlaced fashion. 
     
     
         66 . The patient interface of any one of  claims 59 - 65 , wherein the resistive sensor has a conductive yarn arranged in an interlaced fashion. 
     
     
         67 . The patient interface of any one of  claims 59 - 66 , wherein the processor determines proximity between the patient interface and the patient by comparing a signal generated by the resistive sensor to a predetermined threshold. 
     
     
         68 . A patient interface for sealed delivery of a flow of breathable gas to a patient's airway, the patient interface comprising:
 a sealing structure to form a seal on the patient's face; and   a resistive ink bend sensor coupled to the sealing structure, the sensor adapted to couple with a processor to determine proximity between the sealing structure and the patient's face.   
     
     
         69 . The patient interface of  claim 68 , wherein the resistive ink bend sensor includes a conductive ink. 
     
     
         70 . The patient interface of  claim 69 , wherein the conductive ink is transferred on the sealing structure. 
     
     
         71 . The patient interface of  claim 69 , wherein the conductive ink is transferred on a plastic film. 
     
     
         72 . The patient interface of  claim 71 , wherein the plastic film is assembled to the sealing structure. 
     
     
         73 . The patient interface of any one of  claims 68 - 72 , wherein the sensor generates a signal indicative of at least one of bonding, movement, vibration, humidity, and deflection of the patient interface. 
     
     
         74 . The patient interface of any one of  claims 68 - 72 , wherein the sensor is a unipolar sensing device. 
     
     
         75 . The patient interface of  claim 74 , wherein the sensor includes an ink transferred on one side of the sealing structure. 
     
     
         76 . The patient interface of  claim 74 , wherein the sensor produces an increasing resistance signal as the sensor deflects in one direction. 
     
     
         77 . The patient interface of any one of  claims 68 - 73 , wherein the sensor is a bipolar sensing device. 
     
     
         78 . The patient interface of  claim 77 , wherein the sensor includes ink transferred on both inner and outer surfaces of the sealing structure. 
     
     
         79 . The patient interface of  claim 77 , wherein the sensor produces a signal indicative of any one of the following: (1) the sealing structure is sealed against the patient, (2) the sealing structure is in a nominal position, (3) the sealing structure is overcompressed, (4) the sealing structure is under compressed, and (5) the sealing structure is hyper-extended, 
     
     
         80 . A patient interface for sealed delivery of a flow of breathable gas to a patient's airway, the patient interface comprising:
 a sealing structure to form a seal on the patient's face; and   a shear sensor coupled to the sealing structure, the sensor adapted to couple with a processor to determine proximity between the sealing structure and the patient's face.   
     
     
         81 . The patient interface of  claim 80 , wherein the sensor is one of a pinch shear force sensor and a miniature integrated shear sensor. 
     
     
         82 . The patient interface of  claim 80 - 81 , wherein the sensor produces a signal indicative of at least one of the following: friction, normal force, normal pressure, shear force, pinch shear force, and lateral and vertical instability. 
     
     
         83 . The patient interface of any one of  claims 80 - 82 , wherein the processor determines a sealing condition between the patient interface and the patient based on a shear force signal produced by the sensor. 
     
     
         84 . The patient interface of  claim 83 , wherein the processor determines a lack of contact between the patient interface and the patient when the shear force is approximately zero. 
     
     
         85 . The patient interface of any one of  claims 80 - 84 , wherein the sensor is attached to the sealing structure by an adhesive. 
     
     
         86 . The patient interface of any one of  claims 80 - 84 , wherein the sensor is co-molded with the sealing structure. 
     
     
         87 . The patient interface of any one of  claims 80 - 84 , wherein the processor determines a sealing condition between the patient interface and the patient based on a normal force signal produced by the sensor. 
     
     
         88 . The patient interface of  claim 87 , wherein the processor determines an unintentional leak between the patient interface and the patient's face by:
 comparing the normal force signal to a first predetermined threshold.   
     
     
         89 . The patient interface of  claim 88 , wherein the first predetermined threshold is approximately zero. 
     
     
         90 . The patient interface of any one of  claims 80 - 89 , wherein the processor is configured to adjust the patient interface based on the proximity between the sealing structure and the patient's face to maintain the sealing structure in sealing contact with the patient. 
     
     
         91 . The patient interface of any one of  claims 80 - 90 , wherein the processor is configured to determine stability of the patient interface based on a shear force signal. 
     
     
         92 . The patient interface of  claim 91 , wherein the processor compares an absolute value of the shear force signal to a second predetermined threshold. 
     
     
         93 . The patient interface of  claim 91 , wherein the processor determines the patient interface is destabilized when the absolute value of the shear force signal is greater than the second predetermined threshold. 
     
     
         94 . The patient interface of  claim 91 , wherein the processor determines the patient interface is stabilized when the absolute value of the shear force signal is not greater than the second predetermined threshold. 
     
     
         95 . The patient interface of  claim 93 , wherein the second predetermined threshold is approximately zero. 
     
     
         96 . A patient interface for sealed delivery of a flow of breathable gas to a patient's airway, the patient interface comprising:
 a sealing structure to form a seal on the patient's face; and   a piezoelectric film sensor coupled to the sealing structure, the sensor adapted to couple with a processor to determine proximity between the sealing structure and the patient's face.   
     
     
         97 . The patient interface of  claim 96 , wherein the sensor produces a signal indicating at least one of a seal contact pressure, a contact force, bend, unintentional leak, and a localized interface leak flow. 
     
     
         98 . The patient interface of  claim 97 , further comprising a plurality of piezoelectric film sensors with different pole directions. 
     
     
         99 . The patient interface of any one of  claims 96 - 98 , wherein the sensor detects contact force by being poled across a thickness of the sealing structure. 
     
     
         100 . The patient interface of any one of  claims 96 - 98 , wherein the sensor detects bend and unintentional leak by being poled across a length of the sealing structure. 
     
     
         101 . The patient interface of any one of  claims 96 - 100 , wherein the sensor produces a voltage signal in proportion to a degree of bending of the sensor. 
     
     
         102 . The patient interface of any one of  claims 96 - 101 , wherein the processor determines that the sealing structure is in contact with the patient when the sensor produces a steady voltage signal of a high magnitude. 
     
     
         103 . The patient interface of any one of  claims 96 - 102 , wherein the processor determines that the sealing structure is not in contact with the patient's face when the sensor produces a fluctuating voltage signal of a low magnitude. 
     
     
         104 . The patient interface of  claim 96 , wherein the sensor produces a voltage signal in proportion to temperature. 
     
     
         105 . The patient interface of  claim 96 , wherein the processor determines that the sealing structure is in contact with the patient's face when the sensor produces a voltage signal of a high magnitude. 
     
     
         106 . The patient interface of  claim 96 , wherein the processor determines that the sealing structure is in contact with the patient's face when the sensor produces a voltage signal of a low magnitude. 
     
     
         107 . A patient interface for sealed delivery of a flow of breathable gas to a patient's airway, the patient interface comprising:
 a sealing structure to form a seal on the patient's face;   a piezoresistive positioning structure to secure the sealing structure to the patient's face;   a sensor coupled to the positioning structure to measure tension in the positioning structure, the sensor adapted to couple with a processor to determine tension in the positioning structure.   
     
     
         108 . The patient interface of  claim 107 , wherein the processor is configured to adjust the positioning structure based on the tension in the positioning structure. 
     
     
         109 . The patient interface of  claim 108 , wherein the processor is configured to adjust the positioning structure to maintain the sealing structure in sealing contact with the patient's face. 
     
     
         110 . The patient interface of any one of  claim 108 - 109 , wherein the processor is configured to adjust the positioning structure to reduce its tension when the positioning structure is too tight. 
     
     
         111 . The patient interface of any one of  claim 108 - 110 , wherein the processor is configured to adjust the positioning structure to increase its tension when the positioning structure is too loose. 
     
     
         112 . The patient interface of any one of  claims 107 - 111 , wherein the positioning structure includes a headgear strap that attaches the sealing structure to the patient's face. 
     
     
         113 . The patient interface of any one of  claims 107 - 112 , wherein the sealing structure includes a material that is piezoresistive. 
     
     
         114 . The patient interface of  claim 112 , wherein the headgear strap includes a piezoresistive fabric. 
     
     
         115 . The patient interface of  claim 112 , wherein the sensor includes at least two probes configured to measure an electrical resistance across a length of the strap. 
     
     
         116 . The patient interface of  claim 115 , where each probe includes a conductive strip disposed laterally across the strap. 
     
     
         117 . The patient interface of  claim 116 , wherein the conductive strip is enclosed within a cavity in the positioning structure. 
     
     
         118 . The patient interface of  claim 116 , wherein the conductive strip is sewn into the positioning structure. 
     
     
         119 . The patient interface of  claim 112 , wherein the processor is configured to adjust the length of the strap or elasticity modulus of the strap based on the tension of the strap. 
     
     
         120 . The patient interface of  claim 107 , wherein the positioning structure includes a nylon filament and heater filament that are configured to adjust the length or tension of the positioning structure. 
     
     
         121 . The patient interface of  claim 107 , wherein the positioning structure includes an electro active element responsive to electrical stimulation. 
     
     
         122 . The patient interface of  claim 121 , wherein the electro active element is a piezoelectric film. 
     
     
         123 . The patient interface of  claim 17 , wherein the processor is configured to output the determined tension to an output unit. 
     
     
         124 . The patient interface of  claim 123 , wherein the output unit includes at least one visual indicator. 
     
     
         125 . The patient interface of  claim 124 , wherein the processor provides a first visual indication when the determined tension is at about a predetermined comfortable level. 
     
     
         126 . The patient interface of  claim 124 , wherein the processor provides a second visual indication when the positioning structure is too tight. 
     
     
         127 . The patient interface of  claim 107 , wherein the positioning structure is removably connected to the sealing structure. 
     
     
         128 . A patient interface for sealed delivery of a flow of breathable gas to a patient's airway, the patient interface comprising:
 a sealing structure to form a seal on the patient's face; and   a positioning structure to secure the sealing structure to the patient's face, the positioning structure includes a nylon filament and heater filament to maintain the sealing structure in sealing contact with the patient's face.   
     
     
         129 . The patient interface of  claim 128 , wherein the positioning structure has an adjustable length responsive to a change of the nylon filament and heater filament. 
     
     
         130 . The patient interface of any one of  claims 128 - 129 , wherein the positioning structure has an adjustable tension responsive to a change of the nylon filament and heater filament. 
     
     
         131 . The patient interface of any one of  claims 128 - 130 , wherein the heater filament is a flexible low power heating element. 
     
     
         132 . The patient interface of any one of  claims 128 - 131 , wherein at least one of the nylon filament and heater filament is coated by an electroless plating process. 
     
     
         133 . The patient interface of any one of  claims 128 - 132 , wherein the positioning structure includes a headgear strap. 
     
     
         134 . The patient interface of any one of  claims 128 - 133 , wherein the headgear strap contracts up to 50% of its original length when heated. 
     
     
         135 . The patient interface of any one of  claims 128 - 134 , wherein the positioning structures includes a plurality of filaments joined in parallel. 
     
     
         136 . The patient interface of any one of  claims 128 - 135 , wherein the positioning structures includes a plurality of filaments joined in series. 
     
     
         137 . A patient interface for sealed delivery of a flow of breathable gas to a patient's airway, the patient interface comprising:
 a sealing structure configured to form a seal on a patient's face; and   a piezoelectric element coupled to the sealing structure, the element configured to vary the sealing structure to form a seal on the patient's face.   
     
     
         138 . The patient interface of  claim 138 , wherein the piezoelectric element is attached to the sealing structure. 
     
     
         139 . The patient interface of  claim 138 , wherein the piezoelectric element is molded to the sealing structure. 
     
     
         140 . The patient interface of  claim 138 , wherein the piezoelectric element is disposed in an outer membrane of the sealing structure. 
     
     
         141 . The patient interface of any one of  claims 138 - 140 , wherein the piezoelectric element eliminates an unintentional leak between the sealing structure and the patient's face when stimulated by electricity. 
     
     
         142 . The patient interface of  claim 138 , wherein the piezoelectric element is attached to an inner membrane of the sealing structure. 
     
     
         143 . The patient interface of  claim 138 , wherein the piezoelectric element is disposed within the sealing structure at a position such that when de-energized, the element forms a nominal cushion shape profile. 
     
     
         144 . The patient interface of  claim 143 , wherein the nominal cushion shape profile is a “C” shape profile. 
     
     
         145 . The patient interface of  claim 144 , wherein the element unfurls the sealing structure to form a seal with the patient's face when energized. 
     
     
         146 . An apparatus for sealed delivery of a flow of breathable gas to a patient's airway, the apparatus comprising:
 a sealing structure to form a seal on the patient's face;   a sensor coupled to the sealing structure and configured to generate a sensor signal;   a positioning structure to secure the sealing structure to the patient's face;   a processor configured to determine a sealing condition between the sealing structure and the patient based on the sensor signal, and configured to adjust at least one of the sealing structure and the positioning structure to maintain the sealing structure in sealing contact with the patient's face;   a prediction system that predicts an unintentional leak between the sealing structure and the patient's face based on the sensor signal; and   a learning system that learns how to fit the sealing structure to the patient's face to form a seal.   
     
     
         147 . A method for fitting a patient interface to a patient's face, comprising:
 determining, by a processor, if a patient interface is used;   predicting a leak between the patient interface and the patient's face based on a signal obtained from a sensor;   adjusting the patient interface to maintain the patient interface in sealing contact with the patient's face;   retrieving a historical setting of the patient interface for fitting the patient interface to the patient's face; and   determining a setting to be applied to the patient interface to form a seal with the patient's face.   
     
     
         148 . The method of  claim 147  wherein the sensor is located at the patient interface. 
     
     
         149 . A method for fitting a patient interface to a patient's face, comprising:
 determining, by a processor, if a patient interface is used;   detecting a leak between the patient interface and the patient's face based on a signal obtained from a sensor;   adjusting the patient interface to maintain the patient interface in sealing contact with the patient's face;   retrieving a historical setting of the patient interface for fitting the patient interface to the patient's face; and   determining a setting to be applied to the patient interface to form a seal with the patient's face.   
     
     
         150 . The method of  claim 149  wherein the sensor is located at the patient interface 
     
     
         151 . The method of  claim 147  or  149 , wherein the historical setting is a user preferred setting. 
     
     
         152 . The method of  claim 149 , wherein the historical setting includes a patient interface parameter associated with at least one of a strap length, elasticity modulus of a strap, force, pressure, position, tilt angle and shape. 
     
     
         153 . An apparatus for sealed delivery of a flow of breathable gas to a patient's airway, the apparatus comprising:
 a sealing structure to form a seal on the patient's face, the sealing structure comprising a conductive foam; and   an electrode pair coupled to the conductive foam and configured for generating a sensor signal corresponding to compression of the conductive foam.   
     
     
         154 . The apparatus of  claim 153  further comprising;
 a processor configured to determine a sealing condition between the sealing structure and the patient based on the sensor signal. 
 
     
     
         155 . The apparatus of  claim 154  wherein the processor is configured to compare measurements from the sensor signal to one or more thresholds.